Material breaking device



June 15, 1937- F. H. ARMSTRONG MATERIAL BREAKING DEVICE 5 Sheets-Sheet l Filed March 30, 1934 ww NP www) wm J bw ,f 7 v\ 4 Q m l. 1L. I www ,mw uw ,QN N FQ /NN WW N o/WJ QV www/hwk* Www \\Q\ um, k Nw w. mwN NN Q\ .QN 1 NN NN mw. GNN ImwiQ.; w %N\ NW N .NN Q mwN QN NLN @NQN NN m www June 15, 1937. F. H. ARMSTRONG MATERIAL BREAKING DEVICE Filed March 50, 1954 5 Sheets-Sheet 2 w Mmm mwwm w? :N7 M /fl vu 6N N June 15, 1937. F ARMSTRONG 2,083,976

MATERIAL BREAKING DEVICE Filed March 50, 1954 5 Sheets-Sheet 5 f2.5 127 /An wumnnl Q;

l@ 7 115\ 1167 1107 /119f1z02g67 /125 June 15, 1937. F. H. ARMSTRONG MATERIAL BREAKING DEVICE Filed March 30. 1954 5 Sheets-Sheet 4 QH NN www EN QQ mi www www www N mw NNN i f mwN T f/f 47 ff. w .m2

QN @NN QN June 15, 1937. F. H. ARMSTRONG MATERIAL BREAKING DEVICE Filed March 30, 1954 5 Sheets-Sheet 5 Patented June 15, 1937 UNITED STATES PATENT OFFICE MATERIAL BREAKING DEVICE Application March 30, 1934, Serial No. 718,175

37 Claims.

There has been developed a commercially successful method and apparatus designed to perform the classes of work for which explosives are ordinarily required and used, which method involves merely a proper handling and application of compressed air or other gas at pressures quite low in relation to the pressures developed by explosives ordinarily used in such work. Broadly speaking, the difference in pressure belu tween explosives as ordinarily used and the compressed air or other gas as used in the performance of this method is compensated by the use of a large volume of the compressed air or other gas. In other words, the compressed air method 1.', relies upon the application of a minimum amount of force required in a particular situation coupled with the expansion of a large volume of the compressed air or gas. One of the important i factors in the practiceof this new method is the n relationship between the volume of the charge,

" the vpressure of the charge and the speed with which the charge is applied to the work at hand.

This new method is practiced in two general ways. One is to introduce into a suitable cartridge or container a charge of compressed air or gas of proper volume and at a proper pressure for the particular work at hand and to then suddenly liberate the charge. According to a second method, a cartridge or container may be '3u positioned in or in operative relation to the material to be acted upon and may be connected by piping to a source of compressed gas at some remote point, suitable means being provided for permitting the flow of compressed gas from the,

source of supply into the cartridge or container and for suddenly liberating this charge when it has reached a desired value.

The present invention relates to the new method brieily characterized above. The principal object of the invention is to provide the most eicient forms of apparatus for practicing the method under different conditions.

It is also an object of the invention to provide certain reliable safety characteristics in equipment o; this kind.

It is a further and very important object of the invention to provide a form of apparatus designed to operate with a. minimum of expense 50 and preferably without'any elementof recurring expense other than normal maintenance.

Referring to the drawings,

Figure l isja view in longitudinal section through one form of cartridge or container de- .',5 signed to fulll the objects of' this invention.

.Figure 2 is a similar view through a slightly modied form of cartridge.

Figure 3 is a view in longitudinal section through a cartridge which will be hereinafter referred to as the precharged type as dis- 5 tinguished from the type represented in Figures 1 and 2, which is designed to be charged from a remote point after being placed in or in operative relation to the material to be acted upon.

Figure 4 is a sectional detailed view taken -10 along line 4-4 of Figure 3.

Figures 5, 6 and 'l relate to a form of the remote charged cartridge and more particularly to a method and means for effecting the charging and discharging of such a cartridge. Figure 5 15 illustrates the cartridge in a position in a drill hole formed in a face of coal to be broken down. Figure 6 is a view in longitudinal section illustrating the construction of the cartridge in its simplest'form, and Figure 7 is a view in longitudinal section illustrating the construction of the valve B which governs the charging and discharging of the cartridge.

Figure 8 is .a view in longitudinal section illustrating a modified form of valve for use in the 25 situation illustrated in Figure 5.

Figures 9 and 10 relate to a further alternative form of the precharged cartridge, Figure 10 illustrating in longitudinal section the cartridge itself and Figure 9 illustrating the co truction and 30 method of operation of the device used in conjunction with the cartridge for eiecting the discharge thereof and also for anchoring the cartridge against displacement.

Figure 11 is a view in longitudinal section illus- 35 trating the preferredand perfected form of cartridge design for charging and discharging under control from a remote point.

Figure 12 is a detailed View of a part shown in Figure 11. 40

In Figure 1, there is shown a complete cartridge or container consisting of a long tubular body l of any desired volumetric capacity. It will be understood, of course, that the mechanism of the cartridge may be the same, regardless of the capacity for which it is'designed, the matter of capacity being determined entirely by the requirements o! the work to be performed. In the use of this method and., apparatus to replace ordinary explosives in the mining of coal and similar materials, it has been found that a cartridge f approximately 200 cu. in. of volumetric capacity is quite adequate. Such a cartridge will ordinarily take the form of a relatively long tube having an outside diameter of approximately 3". 55

I'he relation between length and diameter for any desired volumetricn capacity is largely a matter of economics to be developed in relation to particular conditions.

The tube I is provided with caps 2 and 3, which for convenience will hereinafter be referred to as terminal cap and discharge cap respectively. The discharge cap 3 is of a familiar form such as has been used rather extensively in connection with material breaking cartridges employing carbon dioxide and a chemical heater unit as their source of energy. The cap is formed with an axial bore and a plurality of radial discharge openings 29 communicating therewith. The circular line dened by the end of the axial bore in the discharge cap is used in conjunction with a conical valve for sealing the charg of compressed gas within the cartridge. The valve may engage directly with the discharge cap or there may be provided as is shown a special sealing member 6 designed to have engagement with the valve as indicated at 'I. This member may be made of a metal diierent from that of which the valve itself is made or it may be made of the same metal and serve simply as a readily renewable seat for the valve. The valve 5 has an axial extension 8 which, together with a suitably formed bore' in the end of the cap, serves to center and guide the valve.

The valve 5 is secured to one end of the valve rod 4 which extends throughout the length of the cartridge and which carries on its opposite end a control mechanism governing the introduction and release of compressed gas to and from the interior of the cartridge. This mechanism consists of a plunger 9 having a snug sliding t in the bore 22 formed in the terminal cap 2. A suitable cup leather I2 is provided inwardly of the plunger 9 and is held in position by a retaining nut I3. On the opposite end of the plunger 9 there is carried a secondary plunger assembly consisting of the nut IB, opposed cup leathers II and intermediate supporting disc I0. It will be noted that a bore 2I extends through nut I4, placing the chamber 22 in communication with a transverse bore' 20 and the chamber I9, the latter being formed between the two plunger assemblies. There is also a short bore extending from the transverse bore 29 into the pocket 4B of a ball check valve 24. Leading from the seat 30 of the ball check valve is a passage 25 and a communicating transverse passage 2B which opens into the main chamber of the cartridge. It will be noted`that the terminal cap 2 is provided with a plurality of radial ports or bores 28 which, with the parts in normal closed position, lie directly opposite the center of the plunger assembly consisting of the cup leathers II, the disc Il) and nut I4. The main supply pipe I5 and nipple I6 are secured to the terminal cap 2 in communication with a charging passage I1 which communicates through a. short passage I8 with the chamber I 9 formed between the two plunger assemblies. Suitable sealing gaskets M are provided between the ends of the cartridge body and the terminal and discharge caps.

In utilizing a cartridge of this type it is customary to first position it in a drill hole formed in the material to be broken, with a supply pipe extending therefrom to a suitably remote point and there connected to a source of compressed gas. The source, of course, may be of any desired form, eithera receiver charged with high pressure air or other gas, or a suitable high pressure compressor.

.The operation of this device will best be understood by tracing the flow of air from the supply pipe into and through the various passages iormed in the valve and plunger mechanism of the cartridge. Thus, the air ows initially from the supply pipe I5 and nipple I6 through passages I'I and I8 into the chamber I9, thence through radial passage 20 and axial passage 2| into the chamber 22. In connection with this particular device, chamber 22 may be designated as a control chamber. High pressure air also ows from the radial passage 20 through axial passage 23 into ball check valve pocket 46 and past the ball check valve through passages 25 and 26 into the main chamber 21 of the cartridge. Analyzing the effect of the ow of air through the channels just mentioned, it will be observed that immediately upon the introduction of high pressure air into the chamber 22, a force will be exerted upon the end of plunger assembly consisting of the nut I4 and the outermost cup leather I I, this force acting in an axial direction and resulting in axial movement of the entire Valve assembly, thus bringing the valve head 5 into sealing engagement with the discharge cap as indicated at 'I. With the parts in this position, it will be observed that the several radial discharge ports 28 formed in the terminal cap 2 are eiectively sealed against the escape of high pressure air both from the pocket 22 and the chamber I9 by virtue of the two opposed cup leathers I I. In this connection it should be mentioned that the cup leather I2 serves to prevent the ilow of high pressure air from the main chamber 21 into the small chamber I9 between the two plunger assemblies. The flow of high pressure air from the supply pipe I5 into the main chamber of the cartridge through the Various passages, as mentioned above, may be permitted to continue until the pressure value of the charge formed in the main chamber of the cartridge has reached a desired point, which will usually be determined by the judgment of the operator as to the amount of energy required to do the particular work at hand. When the charge Within the cartridge has reached a desired value, the ow of high pressure air into the cartridge through the various channels mentioned may be discontinued by operation of a cut-olf valve positioned in the supply pipe I5 at a point adjacent the source of supply. In order to eiect discharge of the cartridge it is merely necessary to vent the supply pipe I5 to the atmosphere, which results in the following sequence of events:

The reduction in pressure within the supply pipe I5 results instantaneously in a corresponding pressure reduction in chamber I9, passages 20 and 2l and control pocket 22. It should be observed, however, that this reduction in pressure within passage 20 and passage 23 will naturally result in movement of the ball check valve 24 in a manner to seal the passage 23 against the escape therethrough of any high pressure air from passages 25, 26 and from the main chamber of the cartridge. The reduction of pressure in the control pocket 22 immediately results in an axial movement of the entire valve and plunger assembly in a direction to remove the valve 5 from sealing engagement with the discharge cap, due entirely to the preponderating force acting in that direction by reason of the pressure contained in the main chamber 21 acting upon the exposed head of the nut I.3. Simultaneously with the complete opening of the valve assembly, the several discharge ports 28 are placed in communication with the chamber I9, thus providing an auxiliary vent to the atmosphere for the entire system of passages and for the control pocket 22 and the chamber I9. lThe purpose of the auxiliary vent passages 28 is to insure against any tendency toward closing of the valve assembly as a result of a more rapid drop in pressure in the main chamber 21 than in control pocket 22. Thus, once the opening movement of the valve assembly is initiated, it is certain to remain open, thereby permitting the free and unrestricted discharge of the entire volume of high pressure air contained in the chamber 21 through the several radial discharge ports 29.

'I'he construction described above may be broadly characterized as a differential valve mechanism. Perhaps it is well to explain at this point the important relationships between the areas of the various parts which are eiectively subjected to pressure and to point out wherein the differential relation exists. Considering rst the closing of the valve assembly, the principal factor in this movement is' the area of the end plunger assembly consisting of the nut I4 and its associated cup leather II. This area is in effect the same as the cross sectional area of the cylindrical bore 22. Thus, the pressure of the gas introduced into the pocket 22 is effective upon an area equal to the cross sectional area of the bore, the result of which is an axial movement of the plunger assembly I4 and all connected parts in a direction to bring the valve 5 into sealing engagement with the discharge cap. During the entire charging operation and until such time as the discharging operation is initiated, this full force acts to Vhold the valve in sealed position. Under these circumstances, we have not only the pressure acting upon the plunger assembly I4, but also a like pressure acting upon the effective exposed area of the nut I3 and the valve head 5. The effective exposed area of the nut I3 is the full cross sectional area thereof less the cross sectional area of the valve rod 4. The effective exposed area of the valve head 5 is equal to the cross sectional area of the axial bore formed in the discharge cap, also less the cross sectional area of the rod 4. Thus, the force acting upon the nut I3 is in a direction tending to unseat the valve, while the force acting upon the valve head 5 is in a direction tending to seat the valve. It is recalled, however, that until discharge of the cartridge is actually initiated, there is full pressure acting upon the full cross sectional area of the plunger assembly I4. Hence, under these conditions, the forces acting in opposite directions upon the nut I3 and valve head 5 respectively are of no consequence. As soon, however, as the pressure in control pocket 22 has been reduced substantially or exhausted, the relationship between forces acting upon nut I3 and valve head 5 becomes very important. 1n this connection it is pointed out that the cross sectional area of the nut I3 less the area of the valve rod is slightly greater than the cross sectional area of the bore 1n the discharge cap, less the area of the rod, resulting in a preponderating force tending to move the valve assembly toward open position. Thus, there is a definite diierential between Ithe opposed forces acting upon nut I3 and valve head 5 and when the pressure in control pocket 22 has been reduced to a point. below the value of this differential, then the entire assembly moves into open position.

The form of cartridge shown in Figure 2 is is fundamentally the same as that shown in Figure 1. This form, however, has some minor changes and some rather important additions which will be described. Referring to the terminal cap 32, it will be noted that the discharge ports 28 occupy a diiferent position in relation to the normal position of the valve and plunger assembly. As here shown, these passages are just barely covered by one of the cup leathers I I, the arrangement being such that they are irrimediately placed in communication with the chamber between the two plunger assemblies upon initial movement of the plunger. The purpose of this is to provide a more rapid auxiliary release for the control pocket 22. It will also be noted in this connection that the supply of compressed gas is introduced in advance of the plunger assembly I4 as indicated at I8 and that the port I8 is arranged to be covered and sealed by the forward cup leather II upon initial movement of the valve and plunger assembly. There is provided, however, a secondary port 41 communicating with the supply passage I1 and the control pocket 22 for the purpose of permitting introduction of gas from passage I1 should the plunger be overlying port I8.

Aside from the above changes, the terminal cap and plunger assemblies are practically identical to those of Figure l. There is added to this form of cartridge, however, a device calculated to invsure that the valve mechanism nernains in fully open position at each discharge. This device consists of a spring 38 acting upon the nut 31 and supported by a spring cage 39. The cage 39 is perforated as indicated at 40 to permit the passage of air intoand through the same. The spring 38 is compressed when the valve is in closed position and constantly tends to move the valve toward open position. The same area differentials exist in connection with this design as in that described above, the spring being provided merely to assist in the opening movement of the valve and to insure against possible closing movement thereof. The necessity for the spring 3B or some equivalent device lies in the fact that under certain conditions the pressure in the main chamber 21 may reduce more rapidly than that in the control pocket 22,

thereby causing a reversal of the resultant force acting upon the valve assembly. A further reason for this special provision is that the flow of air at high velocity from the main chamber 21 around the enlarged valve head 5 and out through the passage cap creates a considerable friction drag on the valve head which tends to draw the entire valve assembly toward closed position. The eiectiveness of the application of high pressure gas at the pressures and volumes contemplated for use in the cartridges herein described is dependent to a considerable extent upon the speed with which this energy is applied to the work. It is therefore particularly important that the valve be moved quickly and positively to fully open position and that it be retained in that position until the passage has been completed. The spring device illustrated in Figure 2 has been found to be a satisfactory solution for this problem.

Figures 3 and 5 relate to a form of cartridge and method of use somewhat different from the methods and constructions above described. According to this phase of the invention, the

cartridge is designed to be charged at some central chargingpoint and then transported to the point of use, at which, after being placed in operative relation to the work, a suitable device is attached for eiecting discharge of the cartridge by remote control.

Referring to Figure 3, the body 5I of the cartridge is equipped with terminal and discharge caps 52 and 53 respectively. The discharge cap is sealed on a gasket 12 and is provided with a plurality of discharge ports 13. A valve head 16 is designed to have sealing engagement with the end of the discharge cap and is carried by the valve rod 68 which has on its opposite end a plunger assembly slidably fitting the bore 62 formed in the terminal cap 52. In this case the main chamber of the cartridge is indicated at 66. The plunger 66 is formed with two or more gas passages 63 which communicate with the control pocket 62 and with the main chamber 66 of the cartridge. These ports 63, however, are under the control of a disc type check valve consisting of the disc 65, spring 61 and nut 69. A suitable valve 59 is provided in the terminal cap 52 to permit the cartridge to be charged with the aid of a suitable charging clamp. The present invention is not particularly concerned with the form of the charging apparatus, although perhaps it should be pointed out that this consists broadly of a charging nozzle designed to have sealing engagement with the surface immediately surrounding the valve 59 and which is provided with a suitable packed wrench designed to operate the valve 59. When the cartridge is positioned in such a charging clamp and the valve 59 is moved to open position, high pressure gas is permitted to flow through the ports 66 and 6I into the control pocket 62. From the control pocket 62 the gas passes through the several ports 63, past the check valve 65 and into the main chamber 66. It will be observed, however, that the gas cannot pass in a reverse direction from the chamber 66 to the chamber 62. 'Ihis design provides the same general relationship of vital areas as explained above. The introduction of high pressure gas into the control pocket 62 results instantly in the closing of the valve assembly. Likewise a reduction in pressure in the chamber 62 results in opening movement of the valve assembly owing to the differential relation of the areas of the valve head 16 and the surface of plunger @il which is exposed to the pressure in chamber 66.

Centrally positioned in the outer end of the terminal cap 52 is a nut 18 which provides a sealing surface as indicated at 11 for a pressure operated valve 14. This valve has a sliding t within chamber 15 and is uted as indicated at 82 in Figure 5 to permit the passage of air from the control pocket 62 through passage 6I, around the valve and out through the central opening in the nut 18. The pressure in pocket 62 and passage 6i acts alone to force the valve 1d into sealing engagement with the nut 18.

The above description covers the complete cartridge in the form in which it is charged and thereafter transported to the point of use. When the cartridge is ready to be placed in or in operative relation to the material 'to be acted upon, an actuating unit 54 is Screwed into the end of terminal cap 52. This unit consists of a suitn able housing in which is positioned 2 plunger 55 having an extended stem 51 designed to engage the stem 16 of the pressure operated release valve 14 for the purpose of opening the latter and permitting the escape of high pressure air from pocket 62. With the valve 14 in open position the high pressure air escapes from the pocket 62 through a plurality of escape ports 19. The head 55 of the actuating device may be provided with a connection as indicated at I6 for conveying into the actuating device any suitable form of energy transmitting medium. In other words, the plunger 56 may be actuated hydraulically, pneumatically or otherwise. The cylinder Bil in which the plunger 56 operates is provided with several vent ports to prevent the trapping of air. Thus, the cartridge may be discharged from a point as remote as may be desired by simply transmitting Compressed air or hydraulic pressure to the actuating device 56.

Figures 5, 6 and '1 illustrate a slightly diierent construction and method of operation. In Figure 5 the cartridge A is shown positioned in a drill hole formed in the material to be broken down, with tubing l5 extending from the cartridge and having connection at 21 with a remote control valve B. A supply line H2 is connected at lli to the opposite end of this remote control valve.

Referring rst to the cartridge as shown in Figure 6, it will be noted that the discharge cap, valve and valve rod are essentially the same as corresponding parts shown in Figure l. The plunger assembly contained within the terminal cap E62, however, is somewhat different. A plunger' l5@ has sliding fit in the bore 22 formed in the terminal cap and has threaded connection with the end of the valve rod Il. assembly consisting of cup leather l2 and keeper I3 serves to prevent the passage of high pressure air from the main chamber 21 into the control pocket 22. The plunger I0@ is provided with a port 23 which is normally in communication with passages 25 and 26 and consequently with the interior of the cartridge. A ball check valve 24 is provided to permit the flow of high pressure air from chamber 22 into the main chamber 21, but to prevent ilow in the reverse direction. The terminal and discharge caps are suitably sealed on the body of the cartridge by gaskets liti. A suitable connection I6 is provided in the terminal cap for the supply pipe l5.

It has been found that with a cartridge such 7 as shown in Figure 6, the discharging action is not reliable in cases where it is necessary to use a considerable length of small diameter supply pipe between the cartridge and the source of supply of high pressure air or gas. this is simply that the volume of high pressure air introduced in the chamber 22 during the charging operation cannot be exhausted through a considerable length of tubing having a small inside diameter as rapidly as the pressure in the main chamber 21 of the cartridge can be eX- hausted through the discharge cap when the valve moves toward open position. Thus, if the supply pipe I5 is vented to the atmosphere at a point quite remote from the cartridge, the pressure in chamber 22 will immediately begin to drop and the valve'assembly will move toward open position. However, the instant the valve opens, the more rapid escape of high pressure air from the chamber 21 through the discharge cap results in the lowering of the pressure in that chamber more rapidly than the pressure can be lowered in the chamber 22, thus resulting in a reversal of the resultant forces acting upon the A cup leather The reason for lil a passage valve and the valve will move or tend 'to move toward closed position. In order to prevent this uncertain action, there has been provided an automatic supplemental release valve designed to be positioned in the supply pipe line at a point near the cartridge as indicated at B in Figure 5.

'Ihe supplemental release valve B consists of a cylindrical casing in which there is provided a plunger assembly consisting of plungers I6 and |20 with an interposed cup leather H9. The plunger |20 is provided with a reduced axial extension which is tapered as indicated at |23 to form a valve for sealing the passage |24. Axial passages ||1 and |22 are provided in the plungers ||6 and |20 respectively. A ball check valve ||8 is interposed between the passages formed in these two members and serves to permit iiow of high pressure air from the supply line ||2 to the supply line ||5, but to prevent flow in a reverse direction. A spring |26 acts upon the plunger |20 tending to move the entire assembly to the left, thus carrying the valve |23 out of engagement with the seat surrounding the passage |24. At the right end of the valve casing I0 there is provided one or more radial ports |25, placing the interior of the casing in communication with the atmosphere. The supply pipe leading from the cartridge communicates with the passage |24 through fitting |21. The main supply pipe ||2 leading from the source of supply of high pressure air to the valve communicates with ||4 through connector ||3 having threaded connection with the end plug secured in the valve casing.

The operation of the remote control valve B is in many respects similar to the operation of the cartridges described in Figures 1 and 2. High pressure air from the source of supply passes through the supply pipe 2, passage ||4 into a chamber 5 which may be termed a control pocket having much the same functions as the control pockets 22 of Figuresvl and 2. The iirst result of the introduction of high pressure air into the chamber ||5 is to act upon the exposed area of the face of plunger ll6, thereby moving the entire assembly axially toward the right to bring the v alvev |23 into sealing position. This movement is accomplished by the pressure of the gas against the resistance of the spring |26. Simultaneously with this action the high pressure air passes through passage II'I, past check valve ||8, through passages |2I, |22 and |24 into the pipe I5, which carries the air on into the control pocket 22 in the cartridge. When it is desired to effect dischargeoi the cartridge, it is merely necessary to open a relief valve in the supply pipe ||2 at a point adjacent the source of supply, thereby venting the supply pipe ||2 to the atmosphere and causing a pressure reduction in the control pocket ||5. With the pressure reducing in pocket ||5 a point is soon reached at which the pressure acting upon the small'exposed area of the valve |23, plus the force of the spring |26 results in axial movement of the entire plunger and valve assembly toward the left. It will be appreciated that as soon as this movement occurs, the chamber occupied by the spring |25, as well as the passage |24, the supply pipe |5 and the control pocket 22 of the cartridge are placed in communication with the atmosphere through the several exhaust ports |25. Thus, there is provided a rapid outlet for the high pressure gas in pocket 22 and the piping connected therewith which, of course,

results in a rapid reduction oi.' pressure in the pocket 22 and also in rapid and reliable opening of the valve assembly in the cartridge. It should be understood, of course, that the remote control valve B may be placed at any desired point in the supply line extending between the cartridge and the source of supply or that it may even be attached directly to the end of the cartridge. The only limitation is that it be suiiciently closed to avoid the interposition of too much resistance to the escape of high pressure air from the control pocketof the cartridge to the atmosphere. The friction of the air owing at high velocity through piping of small inside diameter is the vital consideration in this matter.

An alternative Yform of remote control valve Y is illustrated in Figure 8. In principle this form of construction involves merely the substitution of air pressure for the coil spring of the preceding form for moving the valve and plunger assembly to open position. In this case the pipe |5 extends between the remote control valve and the cartridge and the pipe ||3 extends between the valve and the source of supply of high pressure air, nipples |21 and ||2 respectively being employed to connect these pipes to the valve. The movable assembly of this valve mechanism consists of a valve member |33 having secured to one end thereof a plunger assembly consisting of plunger |49, cup leather |39 and cup leather keeper |33. The stem |31 of the plunger |49 extends into a pocket |55 formed in the end plug |3|. This pocket is vented to the atmosphere as indicated at |54 to avoid the trapping of air in the pocket. The stem |31 of the plunger is eii'ec- 3 tively sealed at the point where it passes into pocket |55 by means of a suitable hat leather |40. Thus, the cross sectional area of the stem |31 is not exposed to whatever pressure may exist in chamber |48. The valve |33 is provided with gas passages |43 and |45, the former being in communication with the gas chamber |42 at a point adjacent the inlet. The passage 45 communicates with the interior of chamber |48 through a ball check valve |46 and a radial passage |41. At its opposite end the passage |45 communicates with the outlet |53 through a check valve |50, passage |5| and chamber |52.' During charging operation the valv'e |33 is sealed on the valve casing as indicated at |35. At a point just inwardly of the valve seal the casing |30 is provided with a plurality of radial exhaust ports. A hat leather |4| is positioned within chamber |42 and serves to prevent leakage of high pressure gas from this chamber.

With this remote control valve positioned in the supply line at some point between the source of supply and the cartridge to be charged, high pressure air may be permitted to iiow from the source of supply through supply pipe ||3 into the chamber |42 oi the remote control valve. As an immediate result of the introduction of high pressure air or gas into the chamber 42,

" the entire valve and plunger assembly will move to the extreme right by reason of the pressure acting upon the exposed face of keeper |38. Simultaneously, the high pressure gas will ow into the axial passage |45 o! the valve through ports |43 and in opposite directions therefrom, a portion of it passing around the check valve |46 and into the chamber |46 and another portion passing around check valve |50 and into chamber |52. It will be observed that the initial axial movement of the valve and plunger assembly tofil ward the left brings about an immediate seal at the point |35, thus preventing the escape of high pressure gas from the chamber |52 other than to the pipe 5 leading to the cartridge. It should be pointed out in this connection that the face area of plunger |49 which is exposed to pressure existing in chamber |48, is somewhat less than the exposed area of the keeper l38 on which pressure is acting in an opposite direction. It should also be pointed out that during the charging operation the pressure in chamber |52 acts upon the effective cross sectional area of the head of the valve member disposed therein, tending to supplement the force acting upon the Valve and plunger assembly in adirection toward the left.n As pointed out above, theY cross sectional area of the plunger stem |31 is not exposed to the pressure within the chamber |48 by reason of the fact that this stem enters what may be termed a dead end pocket, which is effectively sealed by the hat leather |40. Thus, during the charging operation the high pressure air will ow through passages |43, |45, around ball check |50, through passage |5| into chamber |52 and thence through pipe I5 to the cartridge. When a desired charge has been introduced into the cartridge in this manner, the discharge may be effected by merely exhausting the supply pipe ||3 to the atmosphere by means of a suitable release or venting valve positioned in the line I3 at a point adjacent the source of.supply. As the pressure in chamber |42 drops, the check valves |46 and |50 move to closed position, thus preventing the iiow of high pressure air from chambers |48 and |52 back into the chamber |42. When the pressure valve in chamber |42 has dropped to some predetermined point, then the force acting upon that face of the plunger |49 which is exposed to the pressure in chamber |48 will serve to move the entire valve and plunger assembly toward the right, thus breaking contact at |35 and permitting escape of high pressure gas from the pocket |52 outwardly through the several exhaust or discharge ports. The end |36 of the valve head is transversely slotted in order to avoid blocking the flow of high pressure gas from the pipe |5 into the chamber |52 and thence outwardly to and through the several exhaust ports. It should be pointed out that immediately upon the breaking of the sealed relation as indicated at |35, the pressure which had previously been acting upon the head of the valve tending to move it toward the left, is immediately lowered, thus eliminating this force as a factor in the positioning of the parts. This leaves the device with a trapped quantity of high pressure gas in chamber |48 which acts constantly upon the exposed face of the plunger |49 to hold the plunger and valve assemblies to the extreme right, with the valve |33 in open position, thus providing a rapid escape for the high pressure air flowing back from the control pocket of the cartridge into the chamber |52.

Figures 9 and 10 deal with a cartridge which is essentially the same as that illustrated in Figure 3, the principal difference being that instead of the pressure operated valve 14 of Figure 3, there is employed a suitable disc |86 of steel, fibre or other suitable material, for sealing. the exhaust passage 6| leading from the control pocket 62. In this case discharge of the cartridge is effected by puncturing the disc |86,l thus permitting escape of the high pressure air from control pocket 62 outwardly to the atmosphere. For this purpose there is provided an air gun or equivalent device as shown in Figure 10. This device consists of a cylinder |6| which is capped at one end as indicated at |62 and which is provided at its opposite end with a suitable threaded collar |63. Positioned between the cap |62 and the collar |63 is a flexible sleeve |64 which is suitably secured at its ends as indicated at |65. The cylinder |6| is provided with several ports |13 which permit the passage of compressed iluid through the cylinder to cause expansion of the flexible sleeve |64. The purpose of this arrangement is to effectively seal and anchor the cartridge and air gun in the bore hole formed in the material in which the apparatus may be used.

The mechanism of the air gun consists of a suitable plunger which carries at its outer end a chisel |61 designed to engage and rupture the sealing disc |86. This plunger is normally retained in starting position by a spring latch |18. This latch is in turn controlled by a pressure responsive release mechanism consisting of diaphragm |8| and trip linger |18. The end of the latch is formed with a notch |83 designed to engage a shoulder |84 formed in the plunger and the tip of this spring latch member is tapered as indicated at |85 to facilitate the entering and engagement thereof with the plunger. A supply pipe |16 is connected to the cap |62 and is in communication with the interior of the cylinder |6|. screwed into the end of a cartridge as illustrated in Figure 10.

With the parts assembled as indicated and positioned in suitable drill hole, the first operation is to permit the flow of a suitably compressed i uid into the cylinder |6| through pipe |16. The development of pressure within the cylinder |6| results in the building up of a force on the plunger tending to project it forcefully in an axial direction toward the end of the cartridge with which the gun is associated. Movement of the plunger, however, is delayed until the pressure has reached a desired predetermined value. In the meantime this uid pressure pass-es through the several ports |13 and causes the flexible sleeve |64 to expand into rm sealing and gripping engagement with the walls of the drill hole in which the apparatus is positioned. When the pressure in the cylinder has reached the desired predetermined value, then the diaphragm |8| will be flexed, thus causing the spring latch |18 to be tripped and releasing the plunger which is then forcefully projected, together with the chisel |61 toward the end of the cartridge. The chisel |61 serves to rupture the disc |86 and the high pressure gas in control pocket 62 of the cartridge passes outwardly through a plurality of exhaust ports |12 formed in the end of the air gun. The only conditioning required for a repetition of this operation is the removal of the ruptured disc |86 and the substitution of a new disc for sealing the outlet opening. The cartridge may then be recharged and used in the manner described.

In Figures 11 and 12 there is shown a preferred form of cartridge of the type designed to be charged and discharged after being positioned in the material to be acted upon. This form of cartridge is fundamentally the same as that illustrated in Figure 2, the chief difference being that the exhaust ports 28 are omitted as unnecessary in this design and the function of the spring 38 of Figure 2 is performed by high pressure air. The discharge end of this cartridge is sufficiently like that of Figure 2 that further description is unnecessary. As regards the terminal cap end.

The air gun assembly is adapted to be 'I'.`

it will be observed that there is positioned between the end of the terminal cap and the shoulder provided in the end of the cartridge a heavy steel plate 206 to which is secured a hat leather 208, surrounding vand adapted to seal on the surface of the valve rod 34 which passes therethrough. The plunger assembly is considerably simplied as compared with that of ,Figure 2 and consists of a steel plunger 205, a cup leather II and a keeper 2| I. A suitable ball check 24 with check spring 4I is provided in the plunger 205 as a means for permitting the flow of high pressure air from chamber 2I4 into the main chamberI 2I1 of the cartridge,'but preventing flow in the reverse direction.

The supply line 2I2 extending from the cartridge to a suitable source of supply permits the introduction of high pressure gas into the control pocket 2I4. This results, as in the designs previously described, in axialV movement of the valve and plunger assembly to bring the valve into rm sealing engagement with the end of the discharge cap 33. At the same time, the high pressure air ows from control pocket 2I4 through passage 2I5, around check valve 24, through slots 2I6, passages 25 and 26, into the main chamber 2I1. It is important to note that as the pressure builds up in the main chamber 2I1, the high pressure gas is permitted to vescape from the main chamber rearwardly along the valve rod 34 into the pocket formed between the disc 205 and the cup leather II, the hat leather 208 functioning merely as a check valve under these circumstances. In other words, the pressure of the charge in chamber 2 I'I acting along the valve rod 34 tends to expand the hat leather from sealing engagement with the rod, thus permitting the passage of high pressure gas into the small chamber between the disc 206 and the cup" leather. It will be observed, however, that a reversal of the flow cannot occur when the pressure in chamber 2 I1 falls below the pressure which is trapped in the small pocket. When a charge of desired value has been introduced into the main chamber 2I'I, the discharge is effected, as usual, by venting the supply pipe 2`I2 to the atmosphere by means of a valve positioned in the supply line at a point adjacent the source of supply. This results immediately in the lowering of the pressure in control pocket 2 I4 and, bearinginmindthatthe pressure trapped in the pocket formed between the cup leather II and disc 206 is the same as that of the charge introduced into the chamber 2I'I, it is apparent that this reduction of pressure in chamber 2 I4 immediately results in axial movement of the valve and plunger assembly toward the left. The initial opening of the main discharge valve 5 naturally results in an immediate and extremely rapid drop in pressure within the chamber 2II and it is therefore apparent that the pressure trapped between disc 20E and cup leather I I will be maintained owing to the diierential pressures acting upon the hat leather 208. Thus, the air trapped in the pocket between the disc and cup leather serve to positively move the valve and plunger assembly toward open position and to maintain them in that position. This arrangement provides a positive and extremely rapid discharge of the high pressure air contained in-the chamber 2I`I and eliminates the necessity of an auxiliary remote control valve as illustrated in Figures 5, '7, and 8 and also eliminates the necessity of the double plunger arrangement with auxiliary exhaust ports as illustrated in Figures 1 and 2. At the same time, the air pocket arrangement replaces the somewhat cumbersome spring arrangement illustrated in Figure 2.

The various designs, structures and methods disclosed herein represent to some extent the succession of improvements one over the other but for the most part, are calculated to meet a variety of conditions which cannot be conveniently met by any single construction or method of operation. For example, there are conditions where it is impractical to carry right up to`the point of use a suitable source of high pressure air. Under such conditions it is desirable to provide a form of device which can be brought to the point of use in a charged condition, ready for use. The nature of the source of supply of high pressure air also is an important consideration in determining the type of mechanism to be used. In some cases, it may be advantageous'to charge the various devices from a source of high pressure gas maintained at a constant pressure. In other cases, it may be desirable to generate and introduce the charge in a progressive manner, starting from atmospheric pressure. These and many other considerations have important bearmarily in relation to the problem of mining coal with a view to providing a method and apparatus which will afford the maximum of safety and which will at the same time accomplish the work in a most economical manner and without destroying in any appreciable degree the essential qualities of the coal produced. It should be understood, however, that the invention in all of its aspects is applicable to a wide range of other uses. The entire absence of heat, flame and electricity and the complete safety of the apparatus will commend it to many old and new uses.

Attention is directed particularly to the form of the discharge cap in the constructions illustrated in Figures 2 and 11. As here shown, the discharge ports are inclined rearwardly from the outermost end of the discharge cap. The purpose of this arrangement of the discharge ports is to utilize the force of the discharging gas to produce a reaction tending to hold the cartridge to its work. For example, if the cartridge is placed in a drill hole formed in a face`of coal with the discharge end adjacent the closed end of the drill hole, the high pressure gas issuing out of the rearwardly inclined discharge ports at high velocity will react upon the surrounding walls of the drill hole, producing a resultant force tending to project the entire cartridge farther inwardly toward the closed end of the drill hole. It will be appreciated, of course, that in cases where it is found desirable to reverse the position of the cartridge in the drill hole, that is, position it with the discharge end toward the open end of the drill hole, then the discharge ports 45 should be inclined in the reverse direction in order to provide the desired resultant force tending to hold the cartridge in the drill hole until its work has been accomplished. This matter of holding the cartridge to its work is of greater importance where relatively low pressures are employed than is the case where relatively high pressures are employed, for the reason that the lower pressures act more slowly and hence provide a greater time interval within which the cartridge may be projected from the drill hole by reason of the building up of a pressure between the innermost end of the cartridge and the inner closed end of the drill hole. Thus, where air pressures ranging from 4000 or 5000 pounds up to 10,000 or 12,000 pounds per square inch are used, it is desirable that some means be provided other than the tamping ordinarily employed for retaining the cartridge in the drill hole. It has been found that this requirement is largely satisfied by inclination of the discharge ports as shown. It will be appreciated, of course, that the angle of inclination may be varied to meet diierent conditions.

The variety of structures disclosed may be regarded as indicative of a much Wider range of structural and functional variations of which the invention is susceptible. It should be appreciated, therefore, that many variations of the principles and structural features disclosed are contemplated as within the scope of the invention, it being impractical to make anything like an exhaustive disclosure of even those variations which have been actually and specifically contemplated.

I claim:-

1. In combination, a cartridge having provision for storing a charge of gas under a high pressure, a supply line therefor, means for releasing the charge to a point of use upon a reduction of pressure in the supply line, means between the ends of said supply line for providing a vent orice larger than the minimum crosssectional area of the supply line, upon pressure reduction in said supply line.

2. In combination, a cartridge having provision for storing a charge of gas at high pressure, a supply line therefor, means for releasing the charge to a point of use upon a reduction of pressure in the supply line, means between the ends of said supply line and adjacent to but spaced from the cartridge for venting the latter upon pressure reduction in said supply line.

3. In a material breaking apparatus in which a charge of gaseous medium is stored at high pressure in a casing and is released suddenly to a point of use by the venting of a control charnber which is filled with high pressure gaseous medium while the casing is charged, a pressure control device for eiecting quick venting of such control chamber comprising a vent valve, and means for quickly opening said valve comprising a cylinder having a bore, a piston reeiprocable in said bore, means for supplying compressed gas to said bore at one side or said piston, a check valve for controlling ioW of gas from said bore to the cartridge, and means actuated by said piston for venting the chamber to effect charge release.

4. In a material breaking apparatus in which a charge of gaseous medium is stored at high pressure in a casing and is released suddenly to a' point of use by the venting of a control chamber which is filled with high pressure gaseous medium while the casing is charged, a pressure control device for eiecting quick venting of such control chamber comprising a vent valve and means for quickly opening said valve comprising a cylinder having a bore, a piston reciprocable in said bore, means for supplying compressed gas to said bore at one side of said piston, a check valve for controlling the iiow of gas from said bore to the cartridge, and means actuated by said piston for venting the chamber to effect charge release, said check valve closing automatically when said vent valve is opened.

5. In a material breaking apparatus in which a charge of gaseous medium is stored at high pressure in a casing and is released suddenly to a point of use by the venting of a control chamber which is lled with high pressure gaseous medium while the casing is charged, a pressure control device for eiecting quick ventingr of such control chamber comprising a vent valve and quick acting pressure control means for actuating said valve, said means acting to close quickly said valve when compressed gas is supplied to the cartridge, and to open quickly said valve when the supply of compressed gas to the cartridge is cut off and the cartridge is vented.

6. In a material breaking apparatus, the combination with a blasting cartridge having a casing in which a charge or" gaseous medium is stored at high pressure and embodying means for releasing suddenly the charge including a valve, and controlling means for said valve including a control chamber which is iilled with high pressure gaseous medium While the casing is charged and adapted to be vented to elect opening of said valve, of a pressure controlled device for effecting quick venting of such control chamber comprising a vent valve, and means for quickly opening said vent valve having pressure responsive controlling means.

7. In a material breaking apparatus, the combination with a blasting cartridge having a casing in which a charge of gaseous medium is stored at high pressure and embodying means for re- I`= leasing suddenly the charge including a valve, and controlling means for said valve including a control chamber which is filled with a high pressure gaseous medium While the casing is charged and adapted to be vented to eieet opening of said Valve, of a pressure controlled device for eiecting quick venting of such control chamber comprising a vent Valve and pressure actuated means for quickly opening said valve comprising a cylinder having a bore, a piston reciprocable .1,

in said bore, and valve actuating means operated by said piston.

8. In a material breaking apparatus, the combination with a blasting cartridge having a casing in which a charge of gaseous medium is stored at high pressure and embodying means for releasing suddenly the charge including a valve, and controlling means for said valve including a control chamber which is filled with high pressure gaseous medium While the casing is charged a and adapted to be vented to effect opening of said valve, of a pressure controlled device for eiecting quick venting of such control chamber comprising a vent valve and pressure actuated means for opening and closing said valve com- I prising a piston-actuated valve actuating means operated to close said valve by the charge of gaseous medium owing to said casing.

9. In a material breaking apparatus, the combination with a blasting cartridge having a casing in which a charge of gaseous medium is stored at high pressure and embodying means for releasing suddenly the charge including a valve, and controlling means for said valve including a control chamber which is lled with high pressure gaseous medium while the casing is charged and adapted to be vented to eiect opening of said valve, of a pressure controlled device for effecting quick venting of such control chamber comprising a vent valve and pressure responsive mechanism for actuating said valve eiTective to cause closing movement of said vent valve When gas is supplied to charge the casing.

10. A material breaking device of the character described, comprising a cartridge embodying a. charge receiving chamber having a discharge orifice, a diierential valve mechanism for controlling said discharge orifice, a control pocket containing a reciprocable piston for governlng the action of said differential valve mechanism, means for venting said control pocket to the atmosphere, and means consequent upon movement of the diiTerential valve mechanism and having a vent control valve element embodied in and movable With said piston for accelerating the venting of said control pocket.

11. In a blasting cartridge, a container having a charge receiving chamber and a discharge opening through which the charge may be released, a diierential valve Within said chamber for controlling said discharge opening, means for eiecting initiation of the opening movement Vof said differential valvrarand means includingnan valve element movable with said last mentioned means for thereafter eecting rapid movement of the valve into its Wide open position.

12. In a blasting cartridge, a container having a charge receiving chamber, a discharge orice, a valve adapted to seal said orice, fluid actuated means governing said valve, and means associated with said governing means and automatically operative upon initial opening of said valve for causing said fluid actuated means Suddenly to open widely said orice sealing valve and including a vent control valve embodied in said iluid actuated governing means.

13. A blasting cartridge comprising a casing having a chamber for receiving a charge of high pressure air or gas, release means for said charge comprising a discharge control valve, pressure responsive means for eiecting opening of said discharge control valve when a predetermined blasting pressure is attained within the cartridge and including a pressure-actuated piston connected to said valve for holding the latter closed during building up of the blasting pressure within the cartridge and for opening said valve when said blasting pressure is attained, and means controlled by movement of said piston and rendered active upon initiation of movement of said valve toward its open position including a vent control valve movable with said piston for accelerating movement of said piston suddenly to move said discharge control valve into its wide open position.

14. A blasting cartridge comprising a casing for receiving a charge of high pressure air or gas and a control chamber, releasable valve means for discharging the blasting charge from said charge receiving chamber, a. piston in said control chamber for controlling said valvev means, means for supplying pressure fluid to said control chamber, valve controlled passages in said piston for supplying pressure uid from said control chamber to said charge receiving chamber, means operative to eiect venting of said control chamber upon attainment of a predetermined blasting pressure within the blasting chamber, said passages in said piston `being automatically closed when said control chamber is vented, and

the pressure in said charge receiving chamber effecting movement of said piston in said control chamber to release said valve means when said controls' chamber is vented, and valve means movable with said piston automatically operative upon initiation f opening movement of said ilrst mentioned valve means for further and more freely venting said control chamber to eiect acceleration of movement of said control piston to move said rst mentioned valve means toward a Wide open position.

15. A blasting cartridge comprising a casing having a chamber for receiving a vblasting charge and a discharge orice, a valve for closing said orice, controlling means for said valve governable to eiect exertion of a valve closing and holding pressure on said valve or to effect relief of said pressure to effect valve opening upon attainment of any one of a wide range of blasting pressures in said chamber, and means operative automatically upon a predetermined opening movement of said valve to eiect complete relief of said holding pressure including a vent control valve movable with an element of said controlling means.

16. In a blasting cartridge, a casing having a chamber for receiving a charge of blasting pressure, a control chamber, and a discharge orice,

a piston reciprocable in said control chamber for actuating said valve, means for supplying pressure to said control chamber at the outer side of Said piston for holding said valve closed,

lcheck valve controlled passage means for supplying pressure from the control chamber at the outer side of the piston to said charge receiving chamber, and check valve controlled means for conducting pressure from said charge receiving chamber to said control chamber at the inner side of said piston, said control chamber at the outer side of said piston adapted to be vented when a predetermined blasting pressure is attained in said charge receiving chamber, the pressure in the control chamber at the inner side of said piston acting on the latter when said control chamber is vented to move said piston in a direction to open said oriice controlling valve to release the blasting charge from said charge receiving chamber through said discharge orice.

17. In a blasting cartridge, a casing having a chamber for receiving a. charge of blasting pressure, a control chamber and a discharge orifice, a valve for controlling said discharge orifice, a piston reciprocable in said control chamber having a piston rod connected to said valve for actuating the latter, means forsupplying pressure to said control chamber at the outer side of said piston for holding said valve closed, check valve controlled passage means for supplying pressure from the control chamber at the outer side of the piston to said charge receiving chamber, a cup packing sealingly engaging said piston rod for conducting pressure uid from said charge receiving chamber to said control charnber at the inner side of said piston while preventing flow of pressure from the control chamber to said charge receiving chamber, said control chamber at the outer side of said control piston adapted to be vented when a predetermined blasting pressure is attained in said charge receiving chamber, the pressure in the control chamber at the inner side of the control piston acting on the latter When said control chamber is vented to move the piston in a direction to open said oriiice controlling valve to release the blasting charge from said chargereceiving chamber to said discharge orifice.

18. In a. blasting cartridge, a casing having a chamber for receiving a charge of blasting pressure and a discharge orice, a member secured to said casing and having a control chamber, a plate interposed between said casing and member for separating the control chamber from said charge receiving chamber and having an axial opening, a valve in said casing for controlling said discharge orifice, a piston reciprocable in said control chamber and having a piston rod extending through said plate opening into connection with said valve for actuating the latter, means for supplying pressure to said control chamber at the outer side of said piston for holding said valve closed, check valve controlled passage means in said piston and piston rod for supplying pressure from the control chamber at the outer side of said piston to said charge receiving chamber, and a cup packing secured to said separating plate for sealingly engaging the piston rod, said cup packing permitting flow of pressure from said charge receiving chamber to the control chamber at the inner side of the control piston while preventing ilow Vof pressure from the control chamber to said charge receiving chamber, said control chamber at the outer side of said control piston adapted to be vented when a predetermined blasting pressure is attained in said charge receiving chamber, the pressure in the control chamber at the inner side of said piston acting on the latter when said control chamber is vented to move the piston in a, direction to open said orifice controlling valve to release the blasting charge from said charge receiving chamber through said discharge orifice.

19. In a. blasting cartridge, a container having a. chamber to receive a charge of gas under high pressure and a discharge opening through which the charge may be released, a valve for controlling said discharge opening, a control chamber within the container which is supplied with high pressure gas when the main chamber is charged, a diilerential pressure plunger in the control chamber, a valve rod threadedly connected to the valve and the plunger, a cup leather for packing said plunger, a retaining nut for said cup leather threaded on the valve rod, said plunger and stem having a passageway therethrough to connect the main and control chambers, a check valve in said passageway, and means for feeding high pressure gas to said main and control chambers and for venting gas from said control chamber.

20. In a blasting cartridge, a container having a chamber to receive a charge of gas under high pressure and a discharge opening through which the charge may be released, a valve for controlling said discharge opening, a control chamber within the container which is supplied with high pressure gas when the main chamber is charged, a diierential pressure plunger in the control chamber, a valve rod threadedly connected to the valve and the plunger, a cup leather for packing said plunger, a retaining nut for said cup leather threaded on the valve rod, said plunger and stem having a passageway therethrough to connect the main and control chambers, a check valve in said passageway, and a quick acting venting device for venting said control chamber to eiect movement of the plunger to open said valve.

21. In a blasting cartridge, a container having a chamber to receive a charge of gas under high pressure.. and a discharge opening through which the charge may be released, a valve for controlling said discharge opening, a control chamber within the container which is supplied with high pressure gas when the main chamber is charged, a

, dierential pressure plunger in the control chamthreaded on the valve rod, said plunger and stem having a passageway therethrough to connect the main and control chambers, a check valve in said passageway, and means for effecting a change in pressure condition in said control chamber which will result in opening of said valve and which will maintain said valve open regardless of the speed of discharge from the main chamber.

22. In a blasting cartridge, a container having a chamber to receive a charge of gas under high pressure, a discharge cap for the container having discharge openings and a valve guiding opening, a valve for controlling said discharge openings and having an extension slidable in said valve guide opening, a control chamber within the container which is supplied with high pressure gas when the main chamber is charged, a differential pressure plunger in the control cham-n ber, a valve rod threadedly connected to the valve and the plunger, a cup leather for packing said plunger, a retaining nut for said cup leather threaded on said rod, said plunger and stem having a passageway therethrough to connect the main and control chambers, a check valve in said passageway, and means for feeding high pressure gas to said main and control chambers and for venting gas from said control chamber.

23. In a material ,breaking device, the combination of a container adapted to be charged with high pressure gas at a material breaking pressure and having an outlet therefor, differential valve mechanism controlling said outlet for releasing the charge of material breaking pressure into the material to be broken, a control pocket for governing said differential valve mechanism, said container having inlet and exhaust ports, the former normally in communication with said pocket and the main chamber of said container and the latter normally sealed therefrom but communicable with said pocket consequent upon opening movement of said valve mechanism, the said inlet port being sealed consequent upon said movement, and means for reducing pressure in said control pocket to bring about such movement.

24. In a material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, differential valve mechanism controlling said outlet .for releasing the charge of material breaking pressure into the material to be broken, a control pocket for for governing said diierential valve mechanism, means for reducing pressure in said pocket to cause initial opening movement of said differential valve mechanism, and means yieldingly urging said valve mechanism toward open position.

25. In a material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, differential valve mechanism controlling said outlet for releasing the charge of material breaking pressure into the material to be broken. a control pocket for governing said differential valve mechanism, means for reducing pressure in said pocket to cause initial opening movement of said differential valve mechanism. said container having an exhaust port normally sealed from said pocket but communicable therewith consequent upon opening movement of s-aid valve mechanism, and means yieldingly urging said valve mechanism toward open position.

26. In a material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, diierential valve mechanism controlling said outlet for releasing the charge of material breaking pressure into the material to be broken, a control pocket for governing said differential valve mechanism, means for reducing pressure in said pocket to cause initial opening movement of said diilerential valve mechanism, and means other than the pressure in said container for urging said valve mechanism toward open position.

v27. In a material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, differential valve mechanism controlling said outlet for releasing the charge of material breaking pressure into the material to be broken, a control pocket for governing, said diierentiai valve mechanism, means for reducing pressure in said pocket to cause initial opening movement of said diierential valve mechanism, and means acting in conjunction with the pressure in said container for moving said valve mechanism toward open position and operative to retain the valve mechanism in open position notwithstanding the instantaneous pressure reduction in said container consequent upon the opening of said valve mechanism.

28. In a material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, diii'erential valve mechanism controlli-"f said outlet for releasing the charge of material breaking pressure into the material to be broken, a control pocket for governing said differential valve mechanism, means for reducing pressure in said pocket to cause initial opening movement of said dlierential valve mechanism, said container having an exhaust port normally sealed from said pocket but communicable therewith consequent upon opening movement of said valve mechanism, and a spring for urging said valve mechanism toward open position.

29. In a` material breaking device, the combination of a container adapted to be charged with high pressure gas at material breaking pressure and having an outlet therefor, differential valve mechanism controlling said outlet for releasing the charge of material breaking pressure into the material to be broken, a control pocket for governing said diierential valve mechanism, said container having inlet and exhaust ports, the former normally in communication with said pocket and the main chamber of said container and the latter normally sealed therefrom but communicable with said pocket consequent upon opening movement of said valve mechanism, the said inlet port being sealed consequent upon said movement, and means for reducing pressure in said control pocket to bring about such movement, and a spring for urging said valve mechanism toward open position.

30. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a differential valve mechanism for controlling said oriilce for releasing the charge of material breaking pressure into 'the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said dierential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, a

supply line extending from said connection to a source of supply of compressed gas, and means interposed in said supply line subject to remote control for venting said pocket to the atmosphere.

3l. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orice, a diierential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said diierential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, a

supply line extending from said connection to a source of supply of compressed gas, and an exhaust valve subject to remote control for exhausting said pocket to. the atmosphere, said valve being interposed in said supply line.

32. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a differential valve mechanism for controlling said orifice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said differential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, a supply line extending from said connection to a source of supply of compressed gas, and means interposed in said supply line subject to remote control for venting said pocket to the atmosphere, said means being positioned nearer to said container than to said source of supply.

33. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a diierential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said differential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, a supply line extending from said connection to a source of supply of compressed gas, and means interposed in said supply line subject to remote control for venting said pocket to the atmosphere, said means consisting of a valve having two operative positions, one providing a continuous passage therethrough and the other placing said control pocket in communication with the atmosphere, said valve being controlled by differential pressures.

34. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orice, a differential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken. said container embodying a control pocket, the pressure wherein governs the position and movement of said differential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, a supply line extending from said connection to a source of supply of compressed gas, and means interposed in said supply line subject to remote control for venting said pocket to the atmosphere, said means consisting of a valve having two operative positions, one providing a'continuous passage therethrough and the other placing said control pocket in communication with the atmosphere, said valve being controlled by differential pressures and a spring.

35. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a diierential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said differential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, and a secondary control pocket embodying means for permitting the introduction of and trapping high pressure gas therein, which trapped gas acts upon said differential valve mechanism with opposite effect to that of the rst said control pocket.

36. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a diierential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said diierential Valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, means govern- Aing said connection, and means subject to remote control for actuating said rst means.

37. In a material breaking device, the combination of a container for receiving a charge of compressed gas at material breaking pressure and having a discharge orifice, a differential valve mechanism for controlling said orice for releasing the charge of material breaking pressure into the material to be broken, said container embodying a control pocket, the pressure wherein governs the position and movement of said diierential valve mechanism, a connection through which compressed gas may be introduced into and exhausted from said pocket, pressure actuated means governing said connection, and remote control means for operating said first means to exhaust said control pocket to the atmosphere.

FRANK H. ARMSTRONG. 

